1. Field of the Invention
This invention relates to an improved step and repeat camera for photographing documents onto a microfiche. In one aspect this invention relates to an improved processor for use in a step and repeat camera affording the rapid heat processing of exposed microfiche-sized sheets. Another aspect of the present invention is the positioning of a cut sheet of film for exposing the same to a transparency to impart a latent image of a title onto the sheet and the transporting of the sheet along XY coordinates to impart successive latent images thereto.
2. Description of the Prior Art
The present invention deals with a camera construction for imparting sequentially images onto a light-sensitive sheet of film to impart thereto, upon development, images of documents along XY coordinates of the sheet of film, developing the film and then discharging the finished microfiche with a title imparted to the microfiche and the series of visible images.
Prior art cameras exist for imparting successive images to wide portions of film and to sheets of film and then discharging the film for processing.
Examples of these cameras are shown in U.S. Pat. No. 3,674,367, issued July 4, 1972, to B. M. Chapman; U.S. Pat. No. 3,697,176, issued Oct. 10, 1972 to M. R. Kuehnle et al; and U.S. Pat. No. 3,680,461, issued Aug. 1, 1972 to M. G. Amesbury et al.
The patent to B. M. Chapman discloses a method for handling and positioning film within a camera wherein the film is fed from a supply and severed by a rotary knife, a vacuum platen seizes the length of the film before it is severed and then carries it along mutually perpendicular XY axes to precisely position sections of the film for exposure by a cathode ray tube. After the desired images are applied to the sheet of film the vacuum platen moves directly beneath a film export device 22, and a pair of pinch rollers close upon the film edge to withdraw the film from the camera for storage or further processing. This camera construction is similar to that of applicant's except that applicant's device is provided with a device for contact exposing a title to the film and a transport to transport the sheet of film directly into a heat processor for processing sheet film. Processors within the camera are also known in the art as illustrated in the patent to Kuehnle et al, wherein the exposed image on the film section is processed by a liquid electrostatic toner which develops the image on the film, and which toner image is fused by a heater which engages the surface of the microfiche. Thus, the type of processor which is utilized in the camera can vary according to the type of film utilized and preferably a camera wherein processing is accomplished by a predetermined temperature over a predetermined time period affords a simpler camera than one utilizing xerographic reproduction of the latent image.
The patent to Amesbury et al discloses a drive means for indexing a film along X and Y axis, affording the positioning of the same over the lens. This patent is believed to provide a teaching of moving the platen along coordinates with sufficient precision to permit the repeated exposure of images onto different sections of the film.
Processors for sheets having a coating which is heat developed have taken various forms. One such form is disclosed in U.S. Pat. No. 3,469,077, issued Sept. 23, 1969 to K. H. Petersen et al. This patent discloses a heating device for the development of copy sheets and utilizes a heated drum or a heated shoe about the drum for imparting heat to a copy sheet to afford development of a latent image. This structure however permits the copy sheet to directly contact the drum or the belt which transports it about the drum or to directly contact the heated shoe which is not permitted when developing a fragile photo-sensitive heat-developable coating on one surface of the sheet. This type of coating requires that the coated surface be maintained in a spaced relationship from any other surface during the times the sheet material is being heated to restrict the possibility of removal or displacement of the image-forming coating while the same is heated. Another such developer for film material having the fragile photosensitive heat-developable coating is U.S. Pat. No. 3,439,905, issued Apr. 22, 1969 to G. N. Alseth. In this device the sheet material was held against the surface of a heated drum by means of tiny apertures in the surface of the drum which would pull the uncoated surface of the sheet material into intimate contact with the drum. Thus, the heat from the drum could penetrate through the backing to heat the coating and bring the same to a temperature for a period of time sufficient to develop the image thereon. This type of developing apparatus requires relatively high precision in the heating of the drum to permit the sheet material to be brought up to uniform temperature and maintained for the predetermined period of time sufficient to afford its development.